The present invention relates generally to inkjet printers and, more particularly, to techniques for preventing ink, expelled from inkjet nozzle plates during servicing at a service station, from forming a stalagmite in the printer spittoon.
Conventional inkjet print engines contain three primary components that are generally organized in series. These components are the platen (including a print zone) the spittoon, in which excess print drops are disposed, and the service station where printhead nozzle wiping occurs.
In a conventional inkjet print engine, there may be one or more ink cartridges, or printheads, mounted side by side on a traversing carriage that moves substantially perpendicular to the path of media, such as paper, which pass through the machine, to be printed upon. With ongoing development and improvements in printer technology, spittoon design and function must be considered. For example, in many cases a spittoon can be one common receptacle for receipt of excess ink drops from multiple printheads. There are, however, cases in which incompatibilities between inks have resulted in a requirement of separate spittoons.
Another consideration in modern inkjet service stations, especially when pigment based inks are used, is the accumulation of spitted residual ink within the spittoon. Such accumulation can occur in a manner in which the ink residue forms a "stalagmite" on the bottom of the spittoon. This accumulation, if not relieved, can have a deleterious effect on print quality as the stalagmite grows to a height whereby it interferes with printhead servicing. Thus, it would be advantageous to have an efficient technique for preventing or substantially reducing stalagmite formation in the spittoon. Desirably, such a technique could be utilized during print operations, without interrupting the operations.
In recognition of the stalagmite problem, some conventional modern inkjet printers have been provided with a mechanical chopper that serves to break up the residue. In some cases, such a chopper is a complicated device, requiring a dedicated motor to drive it. While this approach to the stalagmite problem may have some utility, it complicates inkjet printer design and adds to system cost.
In view of the foregoing, it is apparent that there is a need for a stalagmite removal technique that is effective and efficient in use. Desirably, such a technique would eliminate or substantially reduce stalagmite formation in the spittoon, without any need for a complicated, dedicated motor. Implementation of such technique would result in a more efficient printer having lower product weight and cost.